Regarding possible construction methods, it is important to recognize the original wooden beams found in the Bent pyramid to give an idea of how substantial and well crafted the builders could fabricate large peices of wood:
Still in situ within the blocks:
And given as we are told by fresh thinking nothing other than stone could survive for tens of thousands of years, i.e. since the lost civilization built the pyramids, rest assured this wood, stuck into the blocks no less, clearly resides at least within the greater archaic Dynastic period.
Of course these are cedar wood from Lebanon which similar, though circular, massive milled beams are also found in several 1st Dynasty tombs at Saqqara.
When devising construction methods, namely lifting devices, it is important to understand what materials they were capable of manufacturing which obviously massive wooden beams were not a problem. We already know that the AE since the beginnings of Dynastic Egypt were master carpenters well versed in all the foundations of modern carpentry which provides a basis of how they were able to manipulate wooden forms on a larger scale. As was discussed HERE, I argued that the builders must have had the crane which such beams would certainly be up to the task not to mention a host of other devices, such as those described by Herodotus, that could not only be used as mechanical advantage for lifting, transportation, formwork, ect, but quarrying operations as well.

Still in situ within the blocks:

And given as we are told by fresh thinking nothing other than stone could survive for tens of thousands of years, i.e. since the lost civilization built the pyramids, rest assured this wood, stuck into the blocks no less, clearly resides at least within the greater archaic Dynastic period.
Of course these are cedar wood from Lebanon which similar, though circular, massive milled beams are also found in several 1st Dynasty tombs at Saqqara.
When devising construction methods, namely lifting devices, it is important to understand what materials they were capable of manufacturing which obviously massive wooden beams were not a problem. We already know that the AE since the beginnings of Dynastic Egypt were master carpenters well versed in all the foundations of modern carpentry which provides a basis of how they were able to manipulate wooden forms on a larger scale. As was discussed HERE, I argued that the builders must have had the crane which such beams would certainly be up to the task not to mention a host of other devices, such as those described by Herodotus, that could not only be used as mechanical advantage for lifting, transportation, formwork, ect, but quarrying operations as well.